A team of scientists has discovered a group of animals that live without oxygen.

So far science has shown that animals need oxygen to survive. Or at least that’s what was thought. Now a team of scientists has discovered small creatures that can survive and reproduce without this essential element.

As explained by researchers at the Polytechnic University of Marche, in Ancona, Italy, these multicellular organisms, described as new members of the Loricifera group, live in surroundings of poisonous sulfur in the depths of the Mediterranean.

However, say the scientists in the journal “BMC Biology,” the creatures are alive, are metabolically active and apparently reproduce themselves despite a total absence of oxygen in the environment where they live.

The finding, the experts say, has implications that go far beyond the depths of the ocean because it suggests that there may be life in other environments that are also without oxygen, for example on other planets. “Now we intend to go back to the site to see if we can find new surprises,” said one of the researchers.

One of the three new Loricifera discovered has been officially named as Spinoloricus cinzia in honor of the wife of the researcher. The other two, currently called Piliciloricus Rugiloricus, still must be formally classified.

The creatures were discovered during oceanographic expeditions conducted during the last decade in search of fauna in the sediments of the basin of L’Atalante in the Mediterranean. The basin, 200 kilometers (125 miles) from the west coast of Crete, is about 3.5 kilometers (2.2 miles) deep and is almost completely anoxic (lacking oxygen).

In the past they have found bodies of multicellular animals in sediments from anoxic areas, called dead zones, in the Black Sea. But according to Professor Danovaro, when these creatures were discovered, they were thought to be the remains of organisms that had sunk from nearby areas that had oxygen.

What the team found now in the dead zone of L’Atalante were three live animals, two of which contained eggs.

Although it has not been possible to retrieve living animals alive to show they can survive without oxygen, the scientists were indeed able to hatch the eggs in anoxic conditions aboard the ship. The eggs were successfully hatched in an environment completely devoid of oxygen.

“It’s a real mystery how these creatures are able to live without oxygen because up to now we thought that only bacteria could do it,” says Professor Danovaro. “We did not think we could find animals living at this site. We are talking about extreme conditions, an environment full of salt and without oxygen.”

According to the researcher, the discovery of the new Loricifera represents “a tremendous adaptation of animals that evolved in oxygenated conditions.”

The dead zones in the oceans of the world, he adds, are expanding all the time.

In a commentary in the same publication, Dr. Lisa Levin, of the Scripps Institution of Oceanography, said that before this discovery “no one had found any animals able to live and reproduce entirely in the absence of oxygen. Maybe it is because they have been overlooked or because they are extremely rare and therefore it has been impossible to obtain clear evidence, and maybe the scientists have been looking in the wrong places.”

According to Levin, the implications of this finding go beyond the interaction of animals in extreme environments on Earth’s oceans and could help answer questions about the possibility of the existence of life on other planets with different atmospheres.